Reciprocating pump.



H. F. HOFFMAN.

RECIPROCATING PUMP.

APPLICATION FILED ocT. 26. 191e.

4l* 2 SHEFTSAHFEF F. 8

.4/17/ Eli/70H.

Patented Nov.. 27, 19m

H. F. HOFFMAN.

RECIPROCATING PUMP.

APPLICATION man ocv. 2e. 191e.

Fatented Nov. 27, .1917..

2 SHETS-SHEET 2.

www3@ mon/Ws ein HENRY fr. ,Herri/ian, or New yoann. Y.

:anclrnocarncr rUMl?.

Application filedQctober'26` 1916. Serial No. 127,766.

To all whom it may concern.' U y Be it known that I, HENRY F. HOFFMAN, a citizen of the United States, and a resident ofthe Vcity of New York, Stapleton, borough of Richmonchf in the Richmond and State of New-York, `have in"-A vented a new and Improved i Reciprocating" Pump, of which the following is a full, clear, and exact description.

This invention relates Mto reciprocating pumps or the like and `has particular referg ence to such machines adapted part-ici'ilarly,v though not necessarily,eto` ammonia com-` pressors or the like.

Among the objects of the invention is to provide piston and delivery valvemechanisms so designed that thev fluid being pumped will be permitted to pass as 'freely' as possible from'one stage to the next, whereby friction and consequent heating of the parts will be reduced tol aminimum.` Y Vlith the foregoing and -otherobjects 4in view the invention consists in the'arrangement and combination of parts hereinafter described and claimed,a`nd whilethe'inven tion is not restricted to the exact detailsof construction disclosed or suggested herein, still for the purpose of illustrating a prac-4 tical embodiment thereof reference is had to the accompanying drawings, in which like reference charactersy designate the same parts in the several views, and in which A v Figure 1 is a vertical sectional view of a preferred embodiment of the invention;

Fig. 2 is a side elevation of the discharge valve, one of the valve plates being indicated in dotted lines in open position;

Fig. 3 is a side elevation of the piston partly in section on the line 3 3 of Fig. 4;

Figs. 4 and 5 are horizontal sections on the lines 4 4 and 5 5 respectively of Fig. 1;

Figis a vertical sectional detail through the piston on the line 6 6 of Fig. 4;

Fig. 7 is an edge view of one of the piston valves; and

Fig. Sis a transverse sectional detail of the discharge valve stem on the line 8 8 of Fig. 2. y

Referring now more particularly to the drawings, I show a cylinder 10 having a head 11 at one end with a stuiing box 12 through which the piston rod 13 reciprocates. Adjacent this head 11 is the intake 14.

The piston is shown as a whole at 15 secured to thev end of the rodl3 in any suie" able manner.

Secured to the upper end of the cylinder l Iis a delivery headlG with an outlet neck17f. lcounty" of I The 'discharge valve above referred ,"to` is .indicated as a whole at`18 and-comprises` a` disk 19 having a nishedrim` or surfaceat .20 bearing normally 'upon a finished upper ledge or rim V21 of the cylinder. At the ,cen-` ter of the disk is secured a 4stem 22 Qwhichf leads upwardly `through a stuffing box 23 constituting a part of the deliveryhead 16 and including a detachable cap 24 formed with a hole 24 adapted to receivea petcock or the like V(not shown).` VThis pet cock `is designed normally to be kept closed, but is adapted to be opened to permit the escape lof fluid under high pressure in the delivery head, the escape bging; provided` foroby means of a series of longitudinal' grooves 25, extending along the stem 22. Theglength of these grooves is such that they extend beyond `the upper and lower surfaces of the inner or base portion of the stufling box`23.

A heavy coil spring 26 surrounds thestein` 22 and bears at one end upon thetop of the disk holding it normally seated, while the other end `of the spring bears against said" base of the stuffing box'. The upper'endl27 of the stem is formed polygonal for the applicationof a T-wrench or the like, whereby redressing the surfaces 20 and 21 when the cap 24 is removed.

l will now describe more particularly the construction of the piston 15 and the valve plates. The piston is provided at its center with a hub 28 and at its periphery with a cylindrical shell 29 in which are fitted a series of packing rings 30 of any suitable construction for direct coperation with the inner surface of the cylinder. The hub and shell are connected by a series of radial webs 31, shown as four in number extending throughout the full vertical length of the piston, giving thereby ample strength for the structure, but at the same time insuring maximum open space vertically through the piston. The upper ends of the hub 28 and the shell 29 are arranged in the same plane and form, together with the side edges 31 of the webs 31, a plurality of finished seats for a like number of pivoted valve plates, each of which is adapted to oscillate from horizontal position upwardly to an inclined position, such as indicated in Fig. 3, around 'the valve may be rotated for the purpose of a horizontal pivot 33 arranged radially with respect to the piston rod and extending beted at'ts periphery, as shown atB, providing thereby a more reliable seating of the valve plate and facilitating the dressing or grinding operation for maintaining the same in good condition. As will be noted particularly from Fig?, eaclrvalve plate is provided with a stop lug 36 on the opposite side of thc-pivot pin 33 from the main .portion of the plate. This lug enters a groove or -channel at 35 and limits the upward swinging movement of the plate. The periphery of each valve plate likewise is finishedjfor coperation with the valve seat above referred to. It will be appreciated that aseries of four valve plates arranged as indicated, all opening upwardly freely as far as necessary insure i'ree passage of the fluid upwardly through the piston be- Y tween thc several pairs of webs31, and since the-valve plates areheld or limited in their movement to inclined position, they are quick to respond to the closing action. Furthermore, since there are so many of these valve plates and of large capacity, the actual extent of opening movement is comparatively slight. Thereby the quick and effective closing or seating of the valve plates is assured.

The discharge valve with respect to a series of valve plates 37 is essentially the same as the structure of the piston with respect to its valve plates 32, that is to say, the disk 19 comprises a series of radial ribs 3S, each Copies of this patent may be obtained for iive cents each, by addressing the Commissioner of Patents.

The structure surroundingeach of the valve vplates is rab having a plurality of ears 39. Between the ribs are provided openings normally closed or guarded by the-plates 37, each of which has ears pivoted to the adjacent ears 39 Vby means of radial pins 41, but the active surfaces of the plates and the valve plate seats" are 'formed substantially the same asV described above in.r connection with the pisi ton, and the opening movement of the plates 37 is limited` by lugs 42 on the opposite sides of the pivot pins.

According to the design of thispump,

is possible and expedient in the manipula- Y tion of single acting pumps, for ammonia compressors for example, to operate th'e machine at a high degree of eiiiciency without kany danger of overheating the machine or the gas. The devicefis of simple construction and its up-keep is amply provided forv openings, of closure means for the outletV opening comprising a disk having a series oi' openings therethrough in the same plane, a plurality of valve plates swinging up` wardly from but normally closing said openc ings, a centralstemextending from the disk l i and perpendicular thereto, guide means for the stem, said stem being provided with longitudinal grooves extending through the guide means and having a polygonal upper Y end, andv a spring interposed between the disk and said guide means normally holding the disk seated.

HENRY r. HOFFMAN;

Washington, D. C. f 

